Slide caliper with dial indicator and vibrator



SLIDE CALIPEIR WITH DIAL INDICATOR AND VIBRATOR Filed Sept. 26, 1958Sept. 27, 1960 E. w. JOHNSTON 2 Sheets-Sheet 1 lllL IN VE IV TOR EARL n.JOHNSTON B gma/ w Altar/18y Sept. 27, 1960 E. w. JOHNSTON 2,953,854

SLIDE CALIPER WITH DIAL INDICATOR AND VIBRATOR Filed Sept. 26. 1958 2Sheets-Sheet 2 /N l/E N TOR EA KL M. JOHNSTON Alla/n ey Um'w tat SLIDECALIPER WITH DIAL INDICATOR AND VIBRATOR Earl W. Johnston, Worcester,Mass., assignor to United States Steel Corporation, a corporation of NewJersey Filed Sept. 26, 1958, Ser. No. 763,561

6 Claims. (Cl. 33-147) This invention relates generally to measuringdevices and, more particularly, to a slide caliper.

The object of the invention is to provide a caliper which can be made atlow cost and will serve to indicate quickly the diameter of the bearingin a wire-drawing die with a high degree of accuracy.

In a preferred embodiment, the invention comprises a base having a wallupstanding therefrom and a table carried by the wall. One caliper leg isfixed vertically to the wall. A cooperating leg is carried on slide rodsmovable along the wall. Both legs have fingers projecting upwardlythrough a hole in the table for engagement with a die or the like placedthereon.

A complete understanding of the invention may be obtained from thefollowing detailed description and explanation which refer to theaccompanying drawings illustrating the present preferred embodiment. Inthe drawings:

Figure 1 is a plan view;

Figure 2 is a side elevation;

Figure 3 is an end elevation;

Figure 4 is a transverse section taken along the plane of line IVIV ofFigure 2; and

Figure 5 is an enlarged perspective of the caliper legs with partsremoved for clarity.

Referring now in detail to the drawings, the device of my inventioncomprises a length of channel afiording a base 11, a wall 12 upstandingthereon and a shelf 13. Vertically extending bearing blocks 14 and 15are secured to one side of wall 12 in spaced relation. Each block isprovided with a pair of vertically spaced slide ball bearings 16 inwhich a pair of parallel bars 17 are reciprocable. These bars areslidable in holes through a fixed caliper leg 18 secured vertically tothe same side of the wall as the blocks. A movable caliper leg 19 issecured to the bars 17 parallel to leg 18. A counterweighted bell-crank20 is pivoted to wall 12 and its shorter arm is connected by a spring 21to one of bars 17, thus exerting a force constantly tending to move leg19 away from leg 18.

A dial gage 22 is mounted horizontally on block 15 so that its stem isactuated by leg 19 through an extension 23 held against the leg by aspring 24. The gage stem has a finger-operable extension 25 on the otherend by which the movable leg 19 may be manually caused to approach thefixed leg 18. The upper end of each leg has a recess or cut-out 26therein (Figures 4 and 5) provided with a clamp block 27 secured thereinby screws 28. The recesses in the faces of the legs are themselvesrecessed as at 29, (Figures 2 and 5) to accommodate fingers 30'. Theshape of the recesses in the faces of the legs and that of the fingerspermits limited angular adjustment of the fingers about the axes "ice ofscrews 28 by means of screws 31 engaging the outer edges of the fingersat their lower ends Screws 31 are turned into tapped holes drilled alongthe meeting planes of the legs and blocks 27.

A strap 32 is secured to shelf 13 by a screw 33 overhanging one end ofthe shelf with cushioning pads 34 of rubber or like materialtherebetween. A table 35 secured to the inboard end of the strap byscrews 36 overlies legs 18 and 19 and has an opening 37 therein throughwhich the reduced upper ends of fingers 30 project. Thus, merely bypressing extension 25 to close the fingers partially against the forceof crank 20, the article I having a hole therein to be measured, such asa die 38, may be easily placed over the ends of the fingers 30 anddeposited on the table.

A vibrator 39 is mounted on a bracket 40 secured to wall 12 at theopposite end from gage 22. The movable element of the vibrator isconnected to the overhanging end of strap 32. Vibrations imparted to thestrap are transmitted therealong and to table 35, thereby causingcentering of the die relative to the fingers 30 so as to secure anaccurate measurement of its bearing. It will be evident that the finalposition of the movable finger relative to the fixed finger determinesthe reading of gage 22. When the die is removed from the fingers, thecounterweighted crank 20 overcomes the restoring spring of the gagepointer-and forces it to an extreme position determined by stops 41limiting angular movement of the crank. The device is initially set,after properly adjusting fingers '30 by screws 31, by placing a die orgage of known inside diameter on the fingers and then observing the zeroerror of the gage or making the necessary zero adjustment thereof.

A sheet metal cover 42 secured to wall 12 encloses the moving parts. Apush-button switch 43 on table 35 controls vibrator 39. Energization ofthe latter for only a moment suffices to cause accurate centering of adie placed on the table over the caliper fingers 30.

It will be apparent from the foregoing that the invention provides asimple and inexpensive yet accurate 7 and easily manipulable slidecaliper for small distances,

i.e., within the range of a dial gage. The device may be easily adaptedfor use as an outside caliper instead of the inside caliper shown.

Although I' have disclosed herein the preferred embodiment of myinvention, I intend tocover as well any change or modification thereinwhich may be made without departing from the spirit and scope of theinvention.

I claim:

1. A caliper comprising a base having a vertical wall, a verticalcaliper leg fixed to said wall, a cooperating caliper leg parallel tosaid fixed leg, means mounting said cooperating leg for sliding movementalong said wall toward and from said fixed leg, a table overlying saidwall having an opening therethrough above said legs and contact fingerson said legs, respectively, protruding upwardly through said opening.

2. Apparatus as defined by claim 1, characterized by said meansincluding spaced slide bearings on one side of said wall and parallelbars slidable in said bearings, said cooperating leg being secured tosaid bars.

3. Apparatus as defined by claim 1, characterized by a vibrator mountedon said wall and vibration transmitting means extending from saidvibrator to said table.

4. Apparatus as defined by claim 3, characterized by said transmittingmeans being a strap having a cushioned a e-al ae.

leg.

fective to urge the cooperating leg away from the fixed References Citedin the file of this patent UNITED STATES PATENTS Bradbury Mar. 4, 1924Aller Oct. 8, 1940 Neif Mar. 26, 1946 Etchell Sept. 2, 1958

